A boy of mass 50 kg runs up a staircase of 45 steps in 9s. If the height of each step is 15 cm, find his power. (Take g = 10 ms-2)
Answers
Answer:-
Given, mass of body, m = 50 kg
h = 45 x15 = 675 cm = 6.75 m
t = 9 s, g = 10 m
PE = mgh = 50 x 10 x 6.75 = 3375 J
Power of the body = PE / time = Energy / time =
3375 / 9 = 375 W
Answer:
The power is 375 W.
Explanation:
Given,
A boy of mass (m) = 50 kg
No. of steps = n = 45
Time taken (t) = 9 s
Height of each step = 15 cm = 15 / 100 m
To find: find his power
Solution:
Concept involved: Power is the rate of doing work.
Total height of staircase = No. of steps * height of each step
or, Total height of staircase = 45 * 15 / 100 = 6.75 m
Work done would be equal to the Potential Energy possessed by the body.
i.e W = mgh
here, m = 50 kg , g = 10 m/s^2, h = 6.75 m
Substituting the values,
W = 50*10*6.75
And, Power = work done / time
or, P = W / t
or, P = 50*10*6.75 / 9
or, P = 375 W
Therefore, The power is 375 W.